This invention relates to a composite textile fabric, and more particularly, to a composite fabric comprising first and second fabric layers, in which the first, or inner fabric layer, the layer closer to the skin of the wearer, is made from a synthetic yarn, and the yarn of the second, or outer fabric layer, the layer further from the skin of the wearer, is either blended with fibers treated to have anti-microbial properties or the second layer, itself, is treated with an anti-microbial paste.
Most textile fabrics are likely to result in the substantial enclosure of moisture between the wearer""s skin and undergarments or between the undergarments of the wearer and the outerwear due to perspiration of the wearer. When moisture saturation takes place, the body of the wearer is wetted, causing the wearer to feel uncomfortable.
U.S. Pat. No. 5,312,667, owned by Maiden Mills Industries, Inc., describes a composite textile fabric with a first layer made of either polyester or nylon material, and a second layer having a substantial portion of a moisture absorbent material, such as cotton. U.S. Pat. No. 5,547,733, also owned by Malden Mills Industries, Inc., describes a composite textile fabric that includes an inner fabric layer made of a yarn comprising a plurality of fibers, primarily of polyester, which have been rendered hydrophilic, and an outer fabric layer made of a yarn comprising a plurality of fibers, primarily of polyester, which have also been rendered hydrophilic. For each of these patented textile fabrics, the two fabric layers are formed concurrently by knitting a plaited construction so that the layers are distinct and separate yet integrated one with the other.
While the textile fabrics described in both of these Malden Mills patents are advantageous, they are less than desirable. In each of these textile materials, liquid sweat migrates from the inner layer to the outer layer. During migration, the oily mixture of lipids and proteins which is secreted by the wearer migrates along with the liquid sweat. As a result of bacterial decomposition of these lipids and proteins, which become concentrated mainly in the outer layer of the textile fabric, an odor commonly called xe2x80x9cbody odorxe2x80x9d is often produced.
Accordingly, it would be desirable to provide a textile fabric which facilitates liquid moisture transport to promote evaporation and keep the wearer dry, but which also substantially prevents the production of body odor.
Generally speaking, in accordance with the invention, a composite textile fabric for moving liquid moisture away from the skin and evaporating that moisture from the surface of the fabric""s outer layer is provided. The composite fabric includes a first or inner fabric layer, being the layer closer to the wearer""s body, made of a synthetic yarn material which is naturally or has been chemically rendered to be hydrophilic, and a second or outer fabric layer, being the layer further from the wearer""s body, made of a yarn material selected from the group consisting of a moisture-absorbent yarn material such as cotton, or a synthetic yarn material, such as polyester, polypropylene, acrylic or nylon, which has been rendered hydrophilic, or a combination thereof. The inner fabric layer and outer fabric layer are formed concurrently by knitting a plaited construction so that the layers are distinct and separate, yet integrated with one another.
The Washburn equation (see E. A. Wulkow and L. C. Buckles, Textile Research Journal, 29:931 et seq., 1959),
h=2y cos xc3xaa/rpg
where h vertical height of wicking, y=surface tension of the liquid, xc3xaa=contact angle, r=radius of the tube, p=density of the liquid, and 9=gravitational acceleration. This xe2x80x9cwickingxe2x80x9d is the result of capillary action and is enhanced the finer the denier of the fiber of the outer fabric layer and the greater the difference in denier between the yarn fibers of the two layers.
In addition, the denier of the yarn (as opposed to the denier of the yarn fibers) of the inner fabric layer is no greater than the denier of the yarn of the outer fabric layer. This facilitates the horizontal spread of liquid moisture in the outer fabric layer so that moisture is more evenly distributed along this layer, as described by Hollies and his co-workers (see N. Hollies and M. Kaessinger, Textile Research Journal. 26: 829-835, 1956 and 27:8-13, 1957),
S1=y cos xc3xaaArxt/2n
where S1=horizontal distance traveled in time t, y=surface tension of the liquid, rx=effective radius, eA=an apparent advance contact angle, n=viscosity of the liquid, and t=time. This, in turn, further facilitates rapid evaporation of the moisture from the outer layer. The coarser yarn of the outer fabric layer increases that layer""s liquid holding capacity and therefore the xe2x80x9csink effectxe2x80x9d of the outer fabric layer which, in turn, facilitates rapid transfer of the liquid moisture from the wearer""s skin thorough the inner fabric layer to the outer fabric layer.
Significantly, fibers which have been treated to have anti-microbial properties are blended in the yarn of the outer layer of the inventive textile fabric construction. Accordingly, any oily mixture of lipids and proteins that is secreted by the wearer, and then migrates with the liquid sweat from the wearer""s skin through the inner layer, ultimately collects in the outer layer of the fabric, does not decompose, and the production of body odor is therefore substantially prevented.
Preferably, the fibers which have been treated to have anti-microbial properties are selected from nylon or other man-made fibers coated with silver, copper or zinc metal (or ions of any thereof). These fibers are blended with the yarn material of the second or outer fabric layer in an amount between about 0.5 and 30 weight percent. The yarn blended with the treated fiber may be knit into every course of the construction for the highest degree of anti-microbial effect, every other course, every third course, and so on, to vary the level of anti-microbial effect that is desired.
Alternatively, instead of utilizing fibers which have been treated to have anti-microbial properties and blending these fibers in the yarn of the outer layer, an anti-microbial paste or coating may be applied to the outer layer of the inventive textile fabric construction. Preferably, the paste or coating includes at least one of particulate silver, copper, zinc metal or ions of any thereof.
Significantly, fibers which have been treated to have anti-microbial properties are not blended in the yarn of the inner fabric layer. Neither is the inner fabric layer coated with an anti-microbial paste or coating. This is important since there is no advantage to interfere with bacterial growth next to the skin of the wearer. Bacterial growth, per se, is not harmful.
Accordingly, it is an object of the invention to provide an improved composite textile fabric for enhancing the transport of liquid moisture away from the skin.
It is also an object of the invention to provide an improved composite textile fabric having a plurality of synthetic yarn fibers for conducting liquid moisture.
Another object of the invention is to provide an improved composite textile fabric which includes plaited layers for promoting the moisture concentration gradient therebetween.
A further object of the invention is to provide a composite textile fabric which includes an outer moisture absorbent layer and an inner layer made from a synthetic yarn which has been rendered hydrophilic.
Yet another object of the invention is to provide a composite textile fabric which includes an elastomeric yarn to render the fabric stretchable.
Still another object of the invention is to provide a composite textile fabric in which some of the fibers used to produce the fabric have anti-microbial properties.
Yet a further object of the invention is to provide a composite textile fabric which inhibits bacterial proliferation in the outer fabric layer.
Still a further object of the invention is to provide a composite textile fabric which substantially prevents the production of body odor.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the following description.
The invention accordingly comprises fabric and fabric materials having the features, properties and relation of constituents which are exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.